1. Field of the Invention
The present invention relates to a method of alternatingly operating one of several reels arranged following a continuous strip rolling mill, wherein the continuously arriving rolling stock is cut into coil weights of desired lots by means of flying shears provided at the exit of the rolling mill. The invention also relates to a device for operating reels in accordance with the method.
2. Description of the Related Art
Continuous rolling mills which are fed continuously with rolling stock from continuous casting plants, or continuous rolling trains in which the rolling stock lots arriving from a roughing train are connected to each other in front of the first stand of the train, are known in the art. A driver is usually arranged following the continuous rolling mill, wherein a required strip tension at the output of the continuous rolling train is adjustable by means of the driver. Flying shears as well as another driver are arranged following the first driver. The continuously arriving rolling stock is divided by means of the flying shears into such lengths that, after the lots have been wound up, desired coil weights are obtained. A second reel is provided in order to be able to wind up the strip beginning which follows after a relatively short time period the strip end of the strip wound onto the first reel after the transverse cutting of the strip. This is necessary because, as a rule, it is not possible to stop the strip beginning and to pull the previously wound coil from the first reel and subsequently to start winding again onto the first reel.
Turning reels, in which the strip beginning is wound onto the reel in one position of the reel, have also already become known in the art. As soon as the strip rests against the reel without slip, the reel can be moved during its reeling operation into the coil removing position and the second reel of the turning reel is rotated from this position into the position for starting reeling. However, since turning reels are very complicated, they are very expensive and cannot always be used economically following continuous rolling trains.
Separately arranged reels, to which the rolling stock beginning is fed through switches, have also become known. In order to prevent the switches from permanently resting against the rolling stock, the switches must be switched very quickly precisely within that period of time after the end of the rolled strip has passed the switch and before the new beginning of the rolled strip enters the switch. Because of the high outlet speeds of continuous rolling trains, it is necessary to use very fast and complicated rolling switches. However, such switches fail because of the very high outlet speeds of thin strips used today and because of the very short time period between the new strip beginning and the preceding strip end.